This application claims priority from Japanese Patent Application No. 2001-062682, filed Mar. 6, 2001, the contents of which are incorporated hereinto by this reference,
1. Field of the Invention
The present invention relates to a musical apparatus and a method for automatically determining musical notational symbols based on musical composition data, and a computer program for realizing such an apparatus and a method using a computer system, and more particularly to an apparatus and a method capable of determining musical symbols to be exhibited on a musical score as expressed in musical notation according to the prevailing rules with respect to such musical symbols as alteration marks and note descriptions, the alteration marks including sharps, flats and naturals for accidental notes and key signatures, the note descriptions including note names for describing tonalities, chord names and non-root bass notes.
2. Description of the Prior Art
A music composition (or song) data set is usually obtained by recording the performance data which are inputted from a keyboard on which a musical performance is played or the performance data which are created by individually inputting data of performance events using a music sequencer. The key signature, however, will be recorded in the music composition data set, only if it is manually inputted by the composer (or user). In this connection, an electronic musical instrument or a computer having a sequencer program installed therein can exhibit or display a musical score with the notes based on such a music composition data set, but the key signature will not be exhibited as long as it is manually inputted by the composer. And moreover, the key signature is to be determined according to musical expertise, and therefore a key signature manually inputted even by a composer may not always be correct from a musical point of view. The key signature is expressed by using accidentals including a sharp sign (♯) and a flat sign (b). It should be understood herein that the musical flat sign will be represented by an alphabet character xe2x80x9cbxe2x80x9d in the non-superscripted level, where necessary for the sake of typing convenience, as long as it is so understandable from the context. The numeral xe2x80x9c7xe2x80x9d for the seventh chord will not be subscripted, either, for the sake of typing convenience. An accidental sign is a mark which alter the pitch of the natural note to which it is affixed. Other accidentals are double sharp xe2x80x9c♯♯xe2x80x9d, a double flat xe2x80x9cbbxe2x80x9d, and a natural mark. The double sharp mark is usually depicted in the shape similar to the alphabet character xe2x80x9cxxe2x80x9d in the field of music, but it is herein expressed by xe2x80x9c♯♯xe2x80x9d mark for the sake of typing convenience.
Depending on the data format some music composition data sets include data of chord names in addition to data of notes in the music progression. There are two prevailing methods (or formats) of expressing the chord names by their root notes and sometimes with their non-root bass notes, the twelve (12)-note expression and the thirty-one (31)-note expression. The 12-note format of expressing the chord names relies on the twelve notes in an octave under the equal temperament, not discriminating enharmonic notes (e.g. D♯ and Eb), and is conveniently employed in the MIDI (musical instrument digital interface) protocol. This note name expression is very convenient, including some inaccuracy, though. On the other hand, the 31-note format of expressing the chord names relies on the traditional method in the field of music, describing the enharmonic notes differently for the sharped notes and the flatted notes. This note name expression is ruled in the xe2x80x9cXF format protocolxe2x80x9d as proposed by YAMAHA Corporation. Each of the 12-note expression system and the 31-note expression system is closed and consistent within each expression system.
However, if these two systems are used together (or intermingled), one-to-one correspondence will not be ensured, and a definite name may not be determined uniquely in the case of transposition. For example, if an amount of transposition is designated by using the 12-note system (i.e. simply by the number of semitones) where the chord names are expressed by the 31-note system, the two systems are intermingled and the chord names may not always be determined uniquely under the 31-note system after the transposition. The problem is the matter of selecting (or determining) the accidental marks (pitch altering marks) to be used in expressing the chord root or the non-root bass (sometimes described after a slash mark xe2x80x9c/xe2x80x9d). The accidental marks are also used to raise or lower the pitches of individual note temporarily in the musical score. The accidentals are affixed to particular notes relative to the tonality. And therefore, in the case where the inputted music composition data are described in the 12-note expression system, it will be a matter of question which of the enharmonic notes to use for describing such a note in the traditional 31-note expression system.
It is, therefore, a primary object of the present invention to solve the above described drawbacks and to provide a novel type of musical apparatus and a method for automatically determining notational symbols based on musical composition data as well as an apparatus and a method for exhibiting a musical score with such properly determined notational symbols, and a computer program for realizing such apparatuses and methods using a computer system capable of determining musical symbols to be exhibited on a musical score, wherein the determined and expressed musical symbols are expressed properly in musical notation according to the prevailing rules with respect to such musical symbols as alteration marks and note descriptions.
According to the present invention, the object is accomplished by providing an apparatus for determining musical notational symbols based on musical composition data, comprising: a music composition data storing device which stores music composition data representing a length of music containing a progression of notes; a music data readout device which reads out the music composition data; a first selecting device which counts the number of notes which are intrinsic to each of a predetermined plurality of tonalities among the notes contained in a selected span of the length of music, and selects a single optimum tonality or plural tonality candidates based on the counted number of intrinsic notes with respect to each tonality according to a first selection rule; a second selecting device which extracts notes to be subjected to judgment from among a top sub-span of the selected span, examine whether there is a single tonality whose tonic chord includes all of the extracted subject notes among the plural tonality candidates, and, if and only if there is, selects the single tonality to be an optimum tonality; a third selecting device which selects a tonality having a least number of accidental signs among the plural tonality candidates to be an optimum tonality; and a key signature determining device which determines a key signature for the optimum tonality selected by any one of the first, second and third selecting devices.
According to an aspect of the present invention, a musical notational symbol determining apparatus may further comprise a key signature write-in device which writes the determined key signature, into the music composition data storing device.
According to another aspect of the present invention, a musical notational symbol determining apparatus may further comprise a key signature designating input device for inputting a key signature by a user""s operation to designate the key signature; and a key signature altering device which alters the key signature determined by the key signature determining device to the inputted key signature.
According to the present invention, the object is further accomplished by providing an apparatus for determining musical notational symbols based on musical composition data, comprising: a music composition data storing device which stores music composition data representing a length of music containing a progression of notes, together with chord names and a tonality expressed with enharmonic discrimination, each of the chord names being identified by a chord root and a chord type, the chord root being expressed by a name of a basic note plus an amount of pitch alteration; a music data readout device which reads out the music composition data including the notes, the chord names and the key signature; a transposition designation input device which designates an amount of transposition in terms of the number of semitones; a chord root shifting device which shifts the chord roots by shifting the names of the respective basic notes by the amount of transposition and obtains transposed chord roots each of which is expressed by a shifted basic note plus the alteration amount; a first chord root determining device which, in the case where the alteration amount is not zero and the shifted basic note becomes a note expressed by a natural note plus an accidental sign and falling on an accidental note, converts the expression of the shifted basic note to an expression of a natural note which is adjacent to the shifted basic note in the direction of alteration by the accidental sign and adjusts the alteration amount by the amount and in the reverse direction of the conversion of the shifted basic note to obtain a transposed chord name; a second chord root determining device which, in the case where the alteration amount is not zero and the shifted basic note becomes a note expressed by a natural note plus an accidental sign and falling on a natural note, converts the expression of the shifted basic note to an expression of the natural note on which the shifted basic note falls and adjusts the alteration amount by the amount and in the reverse direction of the conversion of the shifted basic note to obtain a transposed chord name; a third chord root determining device which, in the case where the alteration amount is zero, determines the expression of the shifted basic note in view of the tonality after the transposition to obtain a transposed chord name; and a chord name rewriting device which rewrites chord names contained in the stored music composition data according to the transposed chord name obtained by the first, second or third chord root determining device.
According to the present invention, the object is further accomplished by providing an apparatus for exhibiting a musical score based on musical composition data, comprising: a music composition data providing device which provides music composition data representing a length of music containing a progression of notes; a display device which displays a music score based on the music composition data; a tonality determining device which determines an optimum tonality by examining the music composition data to find, with respect to each of plural tonalities, how many notes as represented by the music composition data are contained in the each tonality and by determining an optimum tonality based on the examining; and a display control device which controls the display device to display the music score according to the optimum tonality.
According to a further aspect of the present invention, a musical score exhibiting apparatus may further comprise a chord name exhibit/unexhibit designating device which designates whether or not to exhibit chord names on the music score being displayed; and a chord name exhibit controlling device which controls the display device to exhibit or not to exhibit the chord names on the music score according to the designation.
According to the present invention, the object is further accomplished by providing an apparatus for exhibiting a musical score based on musical composition data which comprises any of the above described apparatus for determining musical notational symbols; and further comprises: a display device; a chord name exhibit/unexhibit designating input device; and a display controlling device which controls the display device to exhibit a musical score with the chord names when the music composition data contains chord names and the chord name exhibit/unexhibit designating input device is designating the exhibit condition, and controls the display device to exhibit a musical score without the chord names when the chord name exhibit/unexhibit designating input device is designating the unexhibit condition.
According to the present invention, the object is further accomplished by providing an apparatus for determining musical notational symbols based on musical composition data, comprising: a music composition data storing device which stores music composition data representing a length of music containing a progression of notes together with a key signature and a major/minor designation; a music data readout device which reads out the music composition data; an accidental sign determining device which determines what accidental signs to be affixed to which of the notes according to the note name, the key signature and the major/minor designation; and an accidental sign affixing device which affixes each of the determined accidental signs to the note to which the each determined accidental sign is to be affixed.
According to a further aspect of the present invention, a musical notational symbol determining apparatus may further comprise: an accidental sign write-in device which writes, into the music composition data storing device, the accidental signs affixed to the notes in correspondence to the notes in the music composition data.
As will be understood from the above description about the apparatus for determining musical notational symbols based on music composition data and the apparatus for exhibiting a musical score based on music composition data, a sequence of the steps each performing the operational function of each of the structural elements of the above apparatuses will constitute a method for determining musical notational symbols and a method for exhibiting a musical score according to the spirit of the present invention.
Further as will be understood from the above description about the apparatus and the method for determining musical notational symbols based on music composition data and the apparatus and the method for exhibiting a musical score based on music composition data, a machine readable medium containing a program instructions executable by a computer system for executing a sequence of the processes each performing the operational function of each of the structural elements of the above musical notational symbol determining apparatus and the above music score exhibiting apparatus or performing each of the steps constituting the above musical notational symbol determining method and the above music score exhibiting method will reside within the spirit of the present invention.
As will be apparent from the description herein later, some of the structural element devices of the present invention are configured by a computer system performing the assigned functions according to the associated programs. They may of course be hardware structured discrete devices. Therefore, a hardware-structured device performing a certain function and a computer-configured arrangement performing the same function should be considered a same-named device or an equivalent to each other,